Straight wire comes in spring brass for piping and rods. The wire may be used for piping on locomotives, cars and structures. Prototype pipe is measured by inside dimension, however for modeling purposes, the outside dimension is used. Rods may be used for truss rods on cars, bridges, water tanks and on other structures. They can also be used for bands on water tanks, throw rods for turnouts, railings, masts and standing rigging on ships.